Reinforced concrete pipe



,4o time possessing requisite strength so that the CHARLEilIzI.` CRTLIDGE, OF LA GRANGE, ILLINOIS.

BENIORCED CONCRETE PIPE.

No. see,44o. y

i Spocication of Lettera Patent.

Patented June 2, 190,5,-

f apiiiimioii iiiapater si', isos. sms'im. mais.

I'o all whom it may concern;

Bc it known -that I, CHARLES H. CART- pinoE, a citizen of the Unitedfstateayresid- -ing at La Grange, in the countyof Cook and C State of Illinois, have inventedcertain new and useful Improvements 4in "Reinforced Y Concrete Pipes, of which the following is a specification.

My invention relates to reinforced "concrete 1g pipes, especially to concrete culvet pipes; and has for its object t produce such a pipe in which the minimum vamount Vof material is combined to produce a 'pipe of maximum strength." f'

To this end my invention consistsin the combinations and ydetails hereinafter set forth and claimed.

In the accompan drawings-Figure 1 is a transverse section view of my improved pipe upon the line 1 of 2. Fig. 2 is a side elevation, partly in section, u on the line 2 of Fig. 1. Fig..3 is a longitu al sectional elevation showinga modifiedform of reinforcement As is well-known there are on man rail: roads a eat number of wooden, pi e and trestle bridges which cross streams of drainage sufficiently small to rmit the use of a'. i com arativel smallv cu vert opening. It has been hitherto impracticable to replace such temporary structures with earthen embankments, because of the high cost of such culverts as have been in use,-the earth work in the niaiuity of cases being a com paratively small proportion of the total expense requirec. l

f One object of my invention is to produce a concrete culvert pipe in which a minimum amount of material is lused, at the same ex nse of re lacin tem orar bi'id 'es of tinlieber by cvert gand Ieartliyen emgbankments may be greatl lessened. As is wellknownconcrete is re atively strong in coinression, while its value in tension is not to relied pon, so that a pipe having the requisiteamount of material to resist compression strains would not resist tensional 'strains to the required degree. It becomes necessary, therefore, to so reinforce .a pipe having only the requisite amount of concrete to resist compression strains; that it will re sist also the tensional strains to whicliit may be subjected.

In carrying out my invention I provide a ,"bediieii iii this pipe having a body of concrete a, and em-i pipe I rvide reinforcing bands of steel b and c, t iebands b being the pipe and the band c being in the form of, strips running longitudinally 4ofV the pipe.v By reference ,to Fig. 1, it will be observed that the rings bare so embedded in the concrete forming the body of the pipe as to be nearer the inner surface of the pipe at the tcp .and bottom portions thereof and nearer the outer surface of the pipe at the opposite diameter-*that is, the reinforcing bands oein the form of rings arranged transversely of cupy the position which will relieve the concrete of its tensile stress under avera e conditionsf of load. This result may e obtainedy either by forming the reinforcing bands in circular form and the concrete forming the .bod ofthe pipe slightly ellipticalL-as indicate in Fig. l-or, as is obvious, thebody of the pipe may be made circular and .the .reinforcing bands elliptical. I prefer, however, to construct 'the pipe, as shown in my drawing, with the concrete ortion slightly elliptical or having one o its axes elongated, and the reinforcement cir-r cular, since by this means the reinforcement is placed in position which will relieve the concrete of its tensile stressand at the saine time owing to the fact that the pipe has. a greater diameter upon one-axis, a means is provided whereby the sections of the pi e may be quickly and readily laid with t reinforcement occupying its proper position.; If the pipesvwere made circular, it

asl

wouldbe necessary to place thereon some distinguishing marks by which to indicate the proper position of the pipes when laying the same.

Longitudinal bands a are arranged approximately at the center of the massv of concrete, hence-as shown in Fig. 1-some 'of them pass outside the transverse bands and others inside the transverse bands. reinforcing pipe made as above described possesses great tensile strength, although a minimum amount of concrete is used. In-

stead of forming the transverse reinforcement of separate rings,-as shown in Fig. 2- I may form this reinforcement of an continuous strip of metal in the form of a spiral, as shown vin Fig. 23h-the construction otherwise being the same in the two forms. One end, of each section pipe is formed with a bell mouth a and the longitudinal reinforcements c are bent downwardly as at c rto form,- in conjunction with the rings c,a

u whole. 'This curvature takes place whether the pipe is'buiit als mcontinuous piece or in Sectione,`-but When-built as a coutiiiuous structure, it invgnriebiy resultsin breakage of the culvert.

i i :The edvantages of-my.i mprqyed pipe-will be readily appreciated Without further fle-- scription.

I claim:

A conduit comprising an elliptical liimiy' .portion of initially plastic material, :ind za. circular reinforcement embedded. within the bod)T ortion, whereby the reinforeeinent lies adjacent the inner Surface of tile body portion at its greater axis and adjacent its outer surface at its Shorter'axis.

A p 4CHARLES ii. CAR'filmen.

f Witnesses: v

NORMAN A. STREET. W. T. JONES. 

